VVC Information
The S1 143bhp EU2 VVC is controlled by the Lucas MEMS 2J ECU common with the early VVC MGFs
The S2 156bhp EU3 VVC is controlled by the Lotus K4 ECU (based on the Lucas MEMS 3)
VVC Failure Modes
ECT Sensor Error Limits to 6K RPM
MAP Sensor Error limits to 6K RPM
VVC Solenoid low resistance (should be 6.6 to 8.8 Ohms)Limits to 5.5K RPM
Cam Position Sensor Limits to 5.5K RPM
Note: Connecting the battery on wrong polarity can blow the ECU VVC control circut, as can running with a low resistance solenoid. Clearly the circuit has no protection.
Lotus S2 K4 ECU VVC Connections
K4 Pin | Wire | Function | Connector |
06 | Blue | VVC Oil Temp Earth | BLACK |
10 | Green Orange | VVC Oil Temp Signal | BLACK |
12 | Black Yellow | VVC Decriment | BLUE |
49 | Brown Black | VVC Increment | BROWN |
The S2 Connector order is LEFT < Blue - Brown - Black > RIGHT VVC Actuator
The S1 connector order is LEFT < Blue - Black - Brown > RIGHT VVC Actuator
Lotus S2 K4 ECU VVC DTC Codes
Code | Description | |
P1336 | S2 Crankshaft Position System Variation Not Learned | |
P1480 | S2 Exhaust flap relay open | |
P1481 | S2 Exhaust flap short circuit | |
P1490 | S2 VVC brown increment solenoid open circuit (Black Yellow) | |
P1491 | S2 VVC brown increment solenoid short circuit (Black Yellow) | |
P1492 | S2 VVC blue decrement solenoid open circuit (Black Brown) | |
P1493 | S2 VVC blue decrement solenoid Short circuit (Black Brown) | |
P1494 | S2 VVC black oil temp sensor LOW short circuit (Green Orange + Blue) | |
P1495 | S2 VVC black oil temp sensor HIGH open circuit (Green Orange + Blue) |
External Resources
VVC Sensors * http://homepage.swissonline.ch/TomsSeven/Navigation2/Map.htm
VVC Sensors * http://www.mgfcar.de/sensor/index.htm
VVC MEMS 2J Description * http://www.mgfcar.de/library/ENGINE_MANAGEMENT_SYSTEM_VVC_MEMS_2J.htm
VVC Mechanism Assembly * http://www.davebence.co.uk/mods_10.htm
VVC Timing * http://forums.mg-rover.org/showthread.php?p=1940938